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whats most irritating is that 100% of my drivability issues with this conversion have to do with trusting the provided parts of a purchased adapter kit, vs making one.

Im on 5 different removals and reinstallations of this T5, all related to what I now am aware is an incorrectly depthed pilot bearing adapter. Its just not designed properly, its much too shallow a mounting point for a stock GM pilot bearing. Had I just figured it out for myself and made my own adapter using a GM flywheel, I wouldnt have been in the position of redoing it so many times.

Now that im in the mindset that every part of the adapter kit might not be designed perfectly, im much more likely to get this figured out for good, but in the process may have damaged a gearbox that only has 8k on it since being rebuilt. Oh well.

Just goes to show, anything worth doing, is worth doing yourself.
Amen to that brother,,,
 

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Discussion Starter · #202 ·
ok, im giving the T5 another try.

Reason being is ive been sitting here with the gearbox turning it in all gears, and nothing, feels great. No clicking, no play, no nothing that would cause worry.

After I pulled the flywheel, I had a good look at the groove cut in the back by my first problems. I finally pulled up a comparison pic of how it looked the first time-



and now-



certainly looks like more, but weirdly, I can find no evidence on the bolts themselves showing they touched. It doesn't seem possible that they are making all that noise and vibration alone, BUT, its so close to my original issue, that there is definitely a likelyhood that this is the culprit. We will see



so what ive decided to do is take that 3mm spacer that I had moved to the front of the flywheel, and move it to the back where I had placed it early on behind the 616.
I moved it around to the front because that was how the kit was designed, and I wanted to move the pilot bearing adapter back by that much, but the clearance is so close, that maybe its touching under load, maybe the flyhweel itself is actually flexing just a tiny bit under load?

anyway, its worth a test install to see what happens with that spacer behind the flywheel again.
 

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Discussion Starter · #204 ·
Ok, I have good news, a little more good news, and a serious blunder that will now be very difficult to resolve.

good news 1-

I have eliminated the metallic noise, there is no more clicking and destruction noises. It seems this was again, the flywheel contacting the adapter plate bolts.

good news 2-

the clutch is now working quite well, so finally have that worked out.

good news 3-

the big tires look good, and only barely touch on some corners. I still have to put the wheel stops in, but they should work well. Secondly moving the bumper up has totally improved the look of the van by a huge amount.

comparison of before and after-




and now for the blunder. I make this admission because this is a crucial step I would never had made doing a 4-speed conversion on a benz, but rocketed right along on this van blowing right by it without thought, and have made some huge work for myself.

Some back history that should be funny considering that I know not to do what I did, and did it anyway. :mrgreen:
Basically, the 5cyl 617 motor is inherently hard to balance, its big and heavy and tall. For this reason, on an undetermined number of the 617 engines, engine balance is often made up on the driven plate of the flywheel. When you go to convert a 617 motor to manual that was formerly automatic, you MUST mark the original automatic flywheel with the crank, and have the manual flywheel match balanced with the original, as often as not, the original flywheel is not a neutral balance.

It suddenly occurs to me what the vibration is at low RPM (and its major). Its because I neglected to match balance the big aluminum flywheel with the existing benz flywheel from the 617 motor. Not only did I forget to do that, I also removed the benz flywheel from the donor motor WITHOUT marking it.

This means that I am pretty much screwed here on getting the balance right with no reference marks. I must have been on the 616 mindset thinking neutral balance, but ive blown it big time.

I can't think of any way to get the balance correct short of pulling the crank out and re-balancing with the flywheel. Unless I find a labor saving scheme to resolve this issue, this is what I think will have to happen now. whoops. heh, this thread is now dedicated to doing every bit of this engine conversion wrong 20 different times, and hopefully getting it to work in the long run.

On the plus side, the crank can probably come out in the van without too much issue.
 

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Discussion Starter · #205 ·
DRZ said:
I think we tend to judge people by ourselves and assume (there's that word again) that people will design something that will do what they say it will do before marketing it to us.
there is a strong possibility that I have a pilot adapter designed for a toyota application, or one cut to that depth. Thats their other major conversion product, and since the adapter would probably look exactly the same, im wondering it thats what happened here
 

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Discussion Starter · #206 ·
a guy over on the benz forum gave me a great idea! (or at least an easier idea than major engine disassembly)
The two blunders I made were not match balancing the flywheel, and not marking the crank.

I can remedy the first one, I will have the aluminum flywheel match balanced to the one I pulled off the motor. Then its a matter of 12 possible positions for the flywheel, and one of them is definitely right. Even if I have to pull and mount the gearbox 12 times, that strikes me as less work and less parts than taking the motor apart.

The plan is to start at 12o'clock, run the motor without the gearbox and see how it vibrates, then go to 6o'clock, 9'oclock, 3'oclock, and so on. I might get lucky, and even if I don't, im bound to get the right position eventually just by process of elimination.

I want to build a jig to hold the motor up while mounted to the diff mount so I can watch vibration, and then I can start this process
 

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How do "They" know where to put the flywheel on the assembly line? It would seem that say, if the engine is at TDC on #1 cylinder, the flywheel weight should be in "this" position. This mess is just too weird for my miniature mind.
 

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Discussion Starter · #209 ·
DRZ said:
How do "They" know where to put the flywheel on the assembly line? It would seem that say, if the engine is at TDC on #1 cylinder, the flywheel weight should be in "this" position. This mess is just too weird for my miniature mind..
I don't know, but if they had provided a dowell pin to locate the flywheel in one position, things could be easier for tinkerers like myself 30 years later mucking things up. :mrgreen:
 

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Discussion Starter · #210 ·
WoodButcher said:
Amazing tinman,,, just amazing. You are a stubborn s.o.b. and will beat it.
If you ever have reason to to be in pass through S.W. CT holler. I'd love to see your van in person and buy you a beer, you certainly deserve it. :thumbup:
definitely, some day this thing might actually be reliable and work! :mrgreen:

thanks!
 

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Discussion Starter · #211 ·
did a test to see if the stock benz flywheel had a biased balance to it

check this out, its got a definite heavy side.

http://www.youtube.com/watch?v=QAX6FiSh ... e=youtu.be

I was told the aluminum flywheel from the kit has a neutral balance to begin with, but now thinking on it, im not sure. I can't remember any drill marks indicating its been balanced. Once thats out im going to spin that too and see what it does.

Maybe I have a biased weighted flywheel incorrectly installed on a engine that already had a biased weighted flywheel in a specific position. That could explain a lot
 

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Discussion Starter · #212 ·
More unfortunate news-

Ive removed the gearbox again, and I have performed the spin test on the aluminum flywheel, and that too has a definite heavy spot, though not as pronounced as the cast iron stock flywheel. It is not a neutral balance as I had hoped.

Since installing the 617, ive driven maybe 12 miles in test drives, and I have more bad news. The imbalanced flywheel fiasco has caused what looks like a rear main seal leak around the crank that has clearly presented itself since the last time the transmission was down (2 days ago). That will have to be fixed now as well, I hope I didn't wipe any bearings also.

here is the aluminum flywheel spin test-

http://www.youtube.com/watch?v=9Lhy4va2 ... e=youtu.be

Both flywheels are now at a machinist getting the one matched to the other
 

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Discussion Starter · #213 ·
long overdue update-

pulled the 83 motor and installed an 85 motor.
83 motor is on a stand for future repair and use in some other project.
85 motor out of a 300CD was installed.

Very busy summer work season is drawing to a close, so hopefully I can get this SOB up and running. Unfortunately I replaced the van with a bigger van a while back, and dont really have a use for this anymore. (once you can lay a 4x8 sheet of drywall or plywood flat in a van, its hard to go back to the smaller version)
Dont want to let it sit and rot, so probably will get it running reliably and sell it.

some new pics. For a little spicy variety, I decided id try and install the new motor through the front of the van. This is technically possible, but I wouldn't do it again. Thought it would be a time saver, but it took almost 4 total hours to get the engine lined up with the motor mounts. and even then I may have cross thread one of them, will resolve later. Some pics of the install process-

83 engine removed-



85 engine ready for teardown-



cramming that sucker in there-





It can only be done at an angle, and just barely at that. Flywheel is off getting matched balanced and this time I MARKED the position of crank to flywheel. :D

I may make a modification to the front lower bracket here along the red line, if that dropped a few inches, you could fire a motor in and out of this van very fast.

 

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DRZ said:
How do "They" know where to put the flywheel on the assembly line? It would seem that say, if the engine is at TDC on #1 cylinder, the flywheel weight should be in "this" position. This mess is just too weird for my miniature mind.
I should think that the flywheel is only "balanced" to itself, and it would not matter which flywheel is slapped to which engine at

assembly time. Just like the crank is balanced to itself and wouldn't matter which block it ends up in. These engines are for

normal cars and trucks, and not meant for the racing crowd, where it would [possibly] make a difference. (Ha)

Uncle Bob
 

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RECox286 said:
DRZ said:
How do "They" know where to put the flywheel on the assembly line? It would seem that say, if the engine is at TDC on #1 cylinder, the flywheel weight should be in "this" position. This mess is just too weird for my miniature mind.
I should think that the flywheel is only "balanced" to itself, and it would not matter which flywheel is slapped to which engine at

assembly time. Just like the crank is balanced to itself and wouldn't matter which block it ends up in. These engines are for

normal cars and trucks, and not meant for the racing crowd, where it would [possibly] make a difference. (Ha)

Having done many clutch jobs and flexplates, never had a balance probem b/c of not putting things back together exactly the

way it came from the factory.

Uncle Bob
 

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Discussion Starter · #216 ·
^^^
The balance is an inherant issue on the early MB 5cyl diesels. Not all are a problem, but a certain number the flywheel or harmonic balancer was installed and balanced with the crank in order to make up a deficiency. Then the whole assembly dropped in the block im guessing

Ive run across it a couple times now. An interesting quirk of these old diesels
 
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